Investigating the Feasibility of Preparing Metal-Ceramic Multi-Layered Composites Using Only the Aerosol-Deposition Technique.

Matej Sadl,Urban Tomc,Hana Ursic

doi:10.3390/ma14164548

Abstract

The preparation of metal–ceramic layered composites remains a challenge due to the incompatibilities of the materials at the high temperatures of the co-firing process. For densification, the ceramic thick-film materials must be subjected to high-temperature annealing (usually above 900 °C), which can increase the production costs and limit the use of substrate or co-sintering materials with a low oxidation resistance and a low melting point, such as metals. To overcome these problems, the feasibility of preparing dense, defect-free, metal–ceramic multilayers with a room-temperature-based method should be investigated. In this study, we have shown that the preparation of ceramic–metal Al2O3/Al/Al2O3/Gd multilayers using aerosol deposition (AD) is feasible and represents a simple, reliable and cost-effective approach to substrate functionalisation and protection. Scanning electron microscopy of the multilayers showed that all the layers have a dense, defect-free microstructure and good intra-layer connectivity. The top Al2O3 dielectric layer provides excellent electrical resistance (i.e., 7.7 × 1012 Ω∙m), which is required for reliable electric field applications.

Highlights

Thick-film multilayer technology is of great value in the electronics industry
A schematic representation and a photograph of the multilayer structure are shown in Figure 1a,b, respectively
The Al2 O3 layer was deposited on top of the Al layer, keeping certain areas free to allow for electrical connections

Summary

Introduction

Thick-film multilayer technology is of great value in the electronics industry. It enables the development and design of a wide variety of products, such as microsystems, electronic circuit boards and micro-electromechanical systems. A hightemperature firing process can be avoided by using aerosol deposition (AD), which is a room-temperature spray-coating method for producing dense, micrometre-thick films. It requires dry powders of approximately micrometre-sized particles that are mixed with a carrier gas to form an aerosol [3]. The high density of the deposited materials is achieved by the hammering effect of powder particles colliding with the surface of the substrate, fragmenting and re-bonding [4,5,6] This deposition mechanism is referred to as a room-temperature, impact-consolidation mechanism [6]. AD is a unique approach to the deposition of ceramic coatings at room temperature, which means the vast majority of research has been conducted on ceramic coatings, such as simple oxides (Al2 O3 [7], TiO2 [8], Y2 O3 [9]), perovskites (Pb(Zr,Ti)O3 [10], BaTiO3 [11])

Methods

Results

Conclusion